The present invention describes novel fluorocompounds which when applied onto fibers and fabrics provide durable finishes with antisoiling properties.
Fluorocarbamates from mono- and diisocyanates have been described previously in various references, such as the references cited above, for improving oil and water resistance of textile surfaces. However, during processing such as washing and drying, a major part of these compounds is lost to the atmosphere and treatment medium, which may cause pollution and operating problems. These problems can be overcome by using reaction products of fluoroalcohols with the biurets of aliphatic or cycloaliphatic isocyanates which give rise to non-volatile and fairly durable textile finishes.
Tris(isocyanato alkane)biurets as used in the invention and their method of preparation are described in U.S. Pat. Nos. 3,124,605 and 3,201,372. It is believed that the unique biuret structure provides strong hydrogen bonding to the fiber substrate.
Further improvement in durability has been achieved by incorporation of a modifier group (R' or R" below) in the reaction product of fluoroalcohols and tris(isocyanato alkane)biurets. A modifier group may be an aromatic, aliphatic, alicyclic compound or mixture of compounds with one or more Zerevitinov* active hydrogen atoms such as any fluorine-free monomeric alcohol or any substituted or unsubstituted fluorine-containing or fluorine-free diol, triol, tetrol, polyol, amine, diamine, triamine, tetramine, polyamine, hydroxyamine, aminothiol, thiol, dithiol, trithiol, tetrathiol, polythiol, hydroxythiol, carboxythiol, monocarboxylic acid, dicarboxylic acid, tricarboxylic acid, aminocarboxylic acid, etc. FNT * Zerevitinov determination is the reaction of an organic compound containing active hydrogen atoms, e.g., --OH, --COOH, --NH, etc., with methylmagnesium halide to give methane which is collected and determined volumetrically.
The novel compounds of this invention impart high oil/water repellency and good soil resistance when applied onto nylon or polyester fiber or fabric. Similar improvements may be achieved when applied to other synthetic or natural fibers or their blends.
The compounds as described in this invention can be applied onto the substrate pure or in combination with other textile or fluoro-finishes, processing aids, lubricants, anti-stains, etc., either from organic solutions or aqueous dispersions by any of the customary procedures such as spraying, dipping, padding, foaming, etc. The compounds can also be blended with other agents which have oil/water repellency and soil release properties and applied to fibers or fabrics.